Design And Realization Of Automatic Test System For Testing Hardware Modules Of Embedded Soft-PLC

With the advent of the information age, the automatic test technology, as appliedwidely in the industry due to it’s test speed, high precision, simple to operate, isbecoming an important means of testing on the production line. The development andimprovement of automatic test technology is of great significance for the modernscience and technology of our country.This paper is based on the localization project of PLC-based control system forwind turbine. In order to solve the drawbacks of low accuracy and low efficiency ofparameter calibration in the original production process with manual debugging, anautomatic test systems based on embedded soft PLC has been developed with theindustry norms and standards for testing, based on the existing manual testingplatform. The system is designed for testing power modules, AIO modules, DIOmodules, PTA modules, CPU modules, CAN modules, fiber optic modules, etc.Based on the requirements analysis, the proposed automatic test system fortesting hardware modules of embedded soft PLC shall be featured of versatility,scalability, standardization, networking capability, automated testing, easy to operateand other characteristics. The structure of the automatic test system is introduced indetail. The modular design and object-oriented programming ideas are applied to thedesign. The automatic test system consists of modules to be tested, upper computer,matrix switches, measuring devices and other peripheral devices. And necessarydrivers and software were correspondingly developed, for the modules to be tested,for upper computer, for FPGA logic of modules, for FPGA logic of matrix switches,for matrix switches to interface with, for programmable digital multimeter to interface,for programmable signal source to interface, for database management and queryprogram. The functions of user management, device management, test managementand query management are presented. Calibration test, routine test and environmenttest are supported. The communications between sub-systems and modules to betested are implemented by Ethernet. The upper computer controls the programmableinstrument by calling wrap VISA (virtual instrumentation software architecture) andSCPI (Standard Commands for Programmable Instruments). The signal source iscontrolled by serial port communication. Automatic test platform for each module hasbeen built and the testing data in full compliance with the performance indicators of the PLC modules.Currently, the automatic test system for testing hardware modules of Embeddedsoft-PLC is used for production of PLC controller for wind turbine,which provides astrong guarantee for the mass production of PLC controller.